Abstract

A Delta 1 - tetrahydrophthalic anhydride is reacted with an amine in the presence of lower fatty acid. Alternatively N-(4hydroxyphenyl)- Delta 1-tetrahydrophthalimide or a salt thereof is reacted with an aralkyl halide. A N-substituted- Delta 1tetrahydrophthalimide compound having herbicidal activity is produced. This compound has the formula

R'' is naphthyl; phenyl; phenyl substituted by 1-3 substituents selected from the group consisting of halogen, nitro, cyano, thiocyano, carboxyl, haloalkyl, lower alkyl and alkylthio; -CH2Y wherein Y is phenyl, naphthyl or phenyl substituted by 1-5 substituents selected from the group consisting of halogen, nitro, lower alkyl and lower alkoxyl; or

WHEREIN Z is phenyl, naphthyl, or phenyl substituted by at least one substituent selected from the group consisting of halogen, nitro, lower alkyl and lower alkoxyl.

Primary Examiner-Joseph A. Narcavage Attorney, Agent, or Firm-Bierman & Bierman 57 ABSTRACT AA tetrahydrophthalic anhydride is reacted with an amine in the presence of lower fatty acid. Alternatively N-(4-hydroxyphenyl)-A -tetrahydrophthalimide or a salt thereof is reacted with an aralkyl halide. A N-substituted-A'-tetrahydrophthalimide compound having herbicidal activity is produced. This compound has the formula I wherein Z is phenyl, naphthyl, or phenyl substituted by at least one substituent selected from the group consisting of halogen, nitro, lower alkyl and lower alkoxyl.

BACKGROUND OF THE INVENTION This invention relates to herbicides particularly to herbicides that contain as active ingredient N- substituted-A-tetrahydrophthalimides. The invention also relates to said N-substitutedA-tetrahydrophthalimides. I

It should be understood that the disclosure in said prior publications is limited only to the method of manufacture and physical properties of specific N- substituted-A'-tetrahydrophthalimides.

SUMMARY OF THE INVENTION It is, therefore. an object of this invention to provide improved herbicides containing as active ingredient the N-substituted-A-tetrahydrophthalimide derivative.

Another object of this invention is to provide novel N-substituted-A -tetrahydrophthalimide derivatives, which exhibit excellent herbicidal effect.

C l O in which R denotes an aryl group or an aralkyl group. The benzene ring of the acyl or aralkyl group may contain one to five substituents selected from the group consisting of halogen, hydroxyl-, nitro-, cyano-, thiocyano-. carboxyl-, haloalkyl-, lower alkyl-, lower alkoxyl-, lower alkylthio-, phenyl and ,,OCH A in which A denotes a phenyl, napthyl, or phenyl substituted by at least one member selected from the group consisting of halogen. nitro, lower alkyl, and lower alkoxyl. 6

The phthalimide derivatives represented by the said general formula may be divided into three groups of compounds as follows:

l..Compounds represented by the formula O] ;N- .....(I) \C in which X is phenyl. naphthyl or phenyl substituted byat least one member selected from the group consisting of halogen. hydroxyl. nitro cyano. thioxyano. carboxyl. haloalkyl. lower alkyl, lower alkoxyl. lower alkylthio. and phenyl.

2. Compounds represented by the general formula in which Y is phenyl. naphthyl, or phenyl, substituted by at least one member selected from the group consisting of halogen, nitro. lower alkyl, and lower alkoxyl. 3. Compounds represented by the general formula \C/NQOCHZZ (III) in which Z is phenyl. naphthyl. or phenyl, substituted by at least one member selected from the group consisting of halogen. nitro, lower alkyl, and lower alkoxyl.

The imides represented by the formula (I) may be manufactured by the method disclosedin the aforesaid Berichte reference in which A-tetrahydrophthalic anhydride and aniline or a derivative thereof are heated in an alcoholic solution. However, such method is not practical from a commercial view point because it affords of a low yield of the product imides.

This problem is solved by the present invention in accordance with which the imides represented by the formula (l) are commercially produced in a higher yield by reacting A -tetrahydrophthalic anhydride with an aryl amine in the presence of lower fatty acids.

Examples of such lower fatty acids include acetic acid, propionic acid and butyric acid. Acetic acid is generally preferred. No limits are set with respect to the amount of lower fatty acid employed. Although it is effective even in a small amount, it usually is used in an amount equivalent to 0.1 to 20.0 times the weight of A -tetrahydrophthalic anhydride. The reaction is facilitated by heating at a temperature in the range 40C-200C, preferably SOT-C. A reaction solvent inert to the reaction, such as for example acetone, dioxane, methyl ethyl ketone. tetrahydrofuran. carbon tetrachloride, benzene, toluene, xylene etc.. may be used. Acid catalyst or dehydrating agent may also be used The imides represented by the formula (ll) are novel and have never been referred to in prior publications. The imides may be manufactured by a method analogous to that which is employed for manufacturing the compounds of the formula (I), which method comprising reacting A-tetrahydrophthalic anhydride with aralkyl amine as follows:

in which Y has the same meaning as in the formula (ll) and Hal denotes halogen atom.

The reaction is carried out in a suitable solvent containing 21 basic substance, and conveniently at a temperature in the range of 50C150C. Examples of the solvents include benzene, toluene, acetone, methyl ethyl ketone, dioxane, tetrahydrofuran and carbon tetrachloride. Example of suitable basic substances include inorganic or organic bases, for example, sodium bicarbonate, potassium carbonate, or pyridine, quinoline, dimethylaniline and triethylamine. r

The imidesrepresented by the formula (III) are also novel-and have never been referred to in prior publications. These imides may be manufactured by reacting N-(4-hydroxyphenyl)-A-tetrahydrophthalimide result- .ing from the reaction between A -tetrahydrophthalic anhydride and 4-aminophenol or a salt of said tetrahydrophthalimide, for example, potassium-, sodium-, ammonium-, or amine salt, with an aralkyl halide as represented by the following formula:

.3 O 8 (I? (lg-o in which M is hydrogenyalkali metal, an ammonium group or an amine residue, Z is as defined with regard to the formula (Ill), and Hal denotes halogen atom.

The reaction takes place in a suitable solvent containing a basic compound, and advantageously under heating at a temperature in the range of Cl50C. As regards the solvent and basic compound. those referred to in the manufacturing method of the compounds of the formula (ll) may be employed.

Examples of the method for manufacturing the compounds represented by the formulae (I), (ll) and (III) are as follows:

REFERENCE EXAMPLE 2 15.2 g (0.1 mole) A-tetrahydrophthalic anhydride and 1 L1 g 4-fluoroaniline were refluxed for 30 minutes under heating in 50 ml of propionic acid. The reaction mixture was cooled. The white capillary crystals which were produced were filtered off and dried. 23.2 g of a compound melting at l52-l54C, and having the formula were obtained. This represented a yield of 94.7%. An elemental analysis of the compound was as follows:

cm H171 0/4 My.

Calcd. for 68.56 4.93 13.05 -5.71 C,,H,2O- .NF I

Analysis found 68.62 4.89 13.18 5.58

REFERENCE EXAMPLE 3 4.6 g of A'-tetrahydrophthalic anhydride were dissolved in 15 g of acetic acid. and 3.2 g of benzylamine were added. After a one hour reflux under heating. a quantity of water was poured into the reaction mixture. The organic layer was extracted with benzene. The extract was dried with magnesium sulphate. purged of excess solvent and distilled under reduced pressure. 6 g of a compound having the formula boiling and at 163C/3 mm Hg were obtained. An elemental analysis of the compound was as follows:

(f/l H17: 01/: N.'/:

Calcd. for 74.66 6.27 l3.26 5.81 (.,-,H ,-,N()

Analysis found 74.48 6.25 13.19 5.60

I REFERENCE EXAMPLE 4 4.6 g A-tetrahydrophthalic anhydride and 5.3 g 3,4- dichlorobenzylamine were refluxed for five hours under heating. in 30 g of ethanol. A suitable amount of water was poured into the reaction mixture. The resulting crystals were filtered off, washed with water once or twice and recrystallized from ethanol. 7.5 g of a compound having theformula and melting at 90C were obtained. An elemental analysis of the compound was as follows:

REFERENCE EXAMPLE 5 The same method as in Reference Example 3 was followed to obtain from 4.6 g A-tetrahydrophthalic anhydride and 3.6 g 4-methylbenzylamine 5.8 g of a compound having a formula UK wa -@415 and a boiling point of l59l60C/3 mm Hg.

REFERENCE EXAMPLE 6 Reference example 4 was repeated with 4.6 g A -tetrahydrophthalic anhydride and 4.] g 4- methoxybenzylamine to obtain 6.4 g of a compound having a formula REFERENCE EXAMPLE 7 4.5 g A'-tetrahydrophthalimide. 5.1 g benzylbromide and 5.4 g anhydrous potassium carbonate were refluxed for 8 hours, with stirring and heating. in g of methyl ethyl ketone. The reaction mixture was filtered while hot. The filtrate was concentrated and distilled under reduced pressure. 6.5 g of a compound having the formula and a boiling point of 163C/3 mm Hg were obtained. An elemental analysis of the compound was as follows:

REFERENCE EXAMPLE 8 4.5 g A'-tetrahydrophthalimide. 4.8 g 3-chlorobenzyl chloride and 3.6 g pyridine were refluxed for 8 hours. under heating, in 100 g of toluene. The reaction mixture was filtered while hot. and the filtrate was concentrated. A suitable amount of water was added to the residue for extraction with benzene. The extractv was dried with magnesium sulphate. purged of excess sol vent. and distilled under reduced pressure. 6.7 g of a compound having the formula Cl C\ m f; \C/ CH2 'LJ and a boiling point of l70C/3 mm Hg were obtained. An elemental analysis of the compound was as follows:

(f/l H.'/' 01/; NM

Calcd. for 65.34 5.l2 l 1.61 5.08 CH N()- .Cl

Analysis found 65.09 5.19 1 L57 5.] l

REFERENCE EXAMPLE 9 4.5 g A'-tetrahydrophthalimide. 4.7 g 2.4-

dimethylbenzyl chloride and 4.5 g triethylamine were refluxed for 8 hours under heating, in 100 g of dioxane. The reaction mixture was filtered. and the filtrate was concentrated. A suitable amount of water was added to the residue. The resulting crystals was filtered off and recrystallized from ethanol. 5.2 g of a compound having the formula and a melting point-of 74C were obtained. An elemental analysis of the compound was as follows:

N-CH -CH 2 3.

CM H17? 01/: N.'/:

Calcd! for 75.80 7.] l l 1.88 .20 CITHIEINOL' Analysis found 75.6l 7.39 ll.77 5 l9 REFERENCE EXAMPLE 10 4.9 g N-(4-hydroxyphenyl)-A-tetrahydrophthalimide. 3.4 g benzylbromide and 3 g anhydrous potassium carbonate were refluxed for 5 hours in 100 g of acetone. The reaction mixture was filtered. and the filtrate was concentrated. The resulting crystals were recrystallized from benzene. 5.9 g ofa compound having the formula and a meltingpoint of l88-l89iC were obtained. An elemental analysis of the compound was as follows:

REFERENCE EXAMPLE l2 4.9 g N-(4-hydroxyphenyl)-A-tetrahydrophthalimide. 3.1 g 4-ethylbenzyl chloride and 3 g anhydrous potassium carbonate were refluxed for 10 hours in g of toluene. The reaction mixture was filtered while hot. and excess solvent was distilled off. The resulting crystals were recrystallized from ethanol. 6.6 g of a compound having the formula and a melting point of l34-l35C were obtained and an elemental analysis as follows:

reaction mixture was filtered in the hot state. and ex-. refluxed for 5 ,hours in 100 g of methyl ethyl ketone. lncess solvent was distilled off. The resulting crystals soluble matter was filtered off. and the filtrate was conwere recrystallized from acetone. 6.8 g of a compound centrated. The resulting crystals were recrystallized having the formula from benzene. 6.0 g of a product having a formula and a melting point of l88-l 89C were obtained. An and a melting point of l7l-l 72.5C were obtained. An

elemental analysis of the compound was as follows: 15 elemental analysis of the compound was as follows:

Indicated in the followin tables are com ounds ac- REFERENCE EXAMPLE 14 g p cording to the invention which have been manufac- 5.3 g sodium salt of N-(4-hydroxyphenyl)-A -tetrahy- 25 tured by the. methods disclosed and have been found to drophthalimide and 3.2 g 4-methylbenzyl chloride was be useful as an active ingredient of herbicides.

Note *1: Figures in the upper rows represent the vertical values which have been calculated for the formulae. Figures in the lower rows represent actual values found by elemental analyses of the compounds numbered 1 to 35.

Note *1: Figures in the top rows represent the vertical values calculated forthe formulae; the figures in the middle rows were determined by elemental analyses (A'-tetrahydrophthalic)anhydride being used as the starting material and the figures in the bottom rows were determinedby elemental analyses (A-tetrahydrophthalimide) being employed as the starting material.

Note *1: Figures given in the upper rows have theoretical values calculated for the formulae and those in the lower rows were determined by elemental analyses.

The imides indicated in the above tables may be employed for herbicidal purposes as is. They are,'however, normally used in the form ofa dilution in an inert liquid or solid. If desired a surfactant or the like may be added to the imides for use in the form of dust, wettable powder, emulsion or granules. Other substances may be incorporated with the imides, such as, for example fertilizers, fungicides, insecticides, nematocides, synergistic herbicides, or other types of herbicides and plant growth regulants.

A great variety of liquids may be employed as carriers for the herbicides of the instant invention. Examples of such liquids include organic liquids such as hydrocarbons, for example, kerosene, benzene and xylene; halogenated hydrocarbons, for example. chlorobenzene and dichloroethylene; alcohols and acetone. Examples of solid carriers include bentonite, kaolin, clay, talc, Japanese acid clay, diatomaceous earth, silica sand and calcium carbonate.

Examples of formulations containing the herbicides of the present invention are as follows.

Dust

parts by weight of the compound No. 3 of Table l were thoroughly mixed with 95 parts by weight of clay to give a dust containing 5% of active ingredient.

Wettable Powder 50 parts by weight of the compound No. 62 of Table l were thoroughly mixed with'45 parts by weight ofdiatomaceous earth and 5 parts by weight of Solpole 8070 (tradename of a surfactant manufactured by Toho Chemical Industries Limited, ofJapan) to obtain a wettable powder containing 50% of active ingredient, which was diluted with water to a desired concentration for spraying.

Emulsion 30 parts by weight of compound No. 39 of Table l weredissolved in a mixture of 35 parts by weight of toluene and 30 parts by weight of ethanol, and 5 parts by weight of Solpole 800 A (tradename of a surfactant manufacture by Toho Chemical Industries Limited, of Japan) were added thereto to form a solution containing 30% of active ingredient. The solution was diluted with water to produce an emulsion having a desired concentration for use as a spray.

Granules A mixture of 6 parts by weight of the compound No. 27 of Table l, parts by weight of bentonite, 50 parts by weight of talc, 16 parts by weight of white carbon and 3 parts by weight of Solpole 9266 (tradename of a surfactant manufactured by Toho Chemical Industries Ltd., of Japan) was thoroughly kneaded together with water in an amount corresponding to 18% of the mixture by means of a kneading machine and granulated by means of a granulator provided with a 8 mmmesh screen. The granules were dried at 60C for 2 hours to give a final product containing 6% of active ingredient. This product was scattered over weeds by means of a suitable device.

Although the herbicides of the present invention may be used for foliar treatment, they are particularly suitable for soil treatment.

The amount of herbicides used is preferably but not in a limitative sense in the range a 3-50 g per are. The herbicides of the present invention are activated by sunshine to give better herbicidal effect. This is illustrated in the following examples l0 and l l in which in the presence of sunshine it is determined that the amount of herbicide used could be reduced to 3 to 20 g per are to produce adequate herbicidal effect.

The invention will now be illustrated with reference to some embodiments in which the numbers of the compounds correspond to those in Tables 1-1 [-2 and 1-3. It should be noted that example 1 to 9 were carried out in a green house whereas examples [0 and l l were carried out outdoors.

EXAMPLE I A Wagner pot of l/2,000 are was filled with paddy soil, and an amount of water was added to the soil and kneaded thoroughly. Evenly spread over the surface of the pot was a prescribed amount of paddy soil in which undesirable weeds such as toothcup (Rolulu imlica Koelme) and millet (Ec/zinoclzloa Crus-galli) were apt to grow. Three-leafed paddy rice seedlings were transplanted in the pot and kept in the paddy fieldstate for 7 days. An aqueous suspension of the wettable powder of the compounds indicated in the following table was sprayed over the water surface of the pot. 25 days later, the growth of the said grasses was compared with the non-treated plot. The results are shown in the following Table 2 in which the herbicidal effect (sproutinginhibiting effect) on the grasses was evaluated and expressed by the figures 0 to 5 according the following scale:

Note: The figure 0. for example. means that the grasses were killed 0 u it) per cent in relation to the non-treated plot.

Table 2-Continued Herbicidal effect Compound Appln rate. Rice seedling Toothcup Millet No g/arc 5 20 0 2 2 34 40 0 5 5 20 0 4 5 l 5 5 20 0 3 4 Nontreated 0 (I (I plot 20 EXAMPLE 2 A Wagner pot of l/2,000 are was filled with paddy soil, and an amount of water was added. After thorough 25 kneading, a prescribed amount of paddy soil in which slender spickrush (Eleocharis acicularis) was apt to grow was spread over the surface of the pot, and paddy rice seedlings in the three-leafed stage were transplanted in the pot and kept in the paddy field state for 7 days. An aqueous suspension of the wettable powder of the compounds, i.e. imides indicated in the following table was sprayed over the water surface of the pot. 25 days-after this treatment, the growth of the plant was investigated. The results are shown in the following table in which the herbicidal effect was evaluated in a manner analogous to example 1.

A pot of l/2,000 are was seeded with radish and millet. When the radish began to sprout the true leaf and the millit was in the two-leafed period, the compounds indicated in the following table were formulated as an aqueous suspension of wettable powder and sprayed on the terrestrial parts of the grasses in the pot. 20 days after the treatment, the growth of the grasses was investigated. The following Table 4 shows is the herbicidal 5 effect of the compounds test which effect was evaluated in terms of figures 0 to 5 according to the following scale;

Fresh Wei ht in treated lot f" Fresh weight in non treatcd plot EXAMPLE ll Paddy rice seedlings were transplanted in a paddy field of clay loam. 7 days later. when the weeds including graminous and broadleaf species were in the 1stleaf stage, an aqueous suspension of wettable powder of compound No. 54 in table [-3 was applied to the soil of the paddy field. After 30 days standing in the natural state, the growth of and the chemical damage incurred by the paddy rice were investigated. For the sake of comparison. similar experiments were carried out with Nip.